Reduction of measurement error in microwave reflectometers by minimum sensitivity calibration

Explicit formulas for the sensitivities of the error corrected reflection coefficient (RC) with respect to the RCs of the calibrating elements, and the invariance of their sum are presented. Under the condition that the sum of the sensitivities is constant, the sum of the absolute values of the sensitivities achieves a global minimum if the measured RC coincides with the altitude centre of the triangle formed by the RCs of the calibrating elements, or which one of the RCs of the calibrating elements. In the examples, 8 dB error reduction was found.